Biofilm represents a way of life that allows greater survival of microorganisms in hostile habitats. Campylobacter jejuni is able to form biofilms in vitro and on surfaces at several points in the poultry production chain. Genetic determinants related to their formation are expressed differently between strains and external conditions are decisive in this respect. Our approach combines phylogenetic analysis and the presence of seven specific genes linked to biofilm formation in association with traditional microbiology techniques, using Mueller Hinton and chicken juice as substrates in order to quantify, classify, determine the composition and morphology of the biomass of simple and mixed biofilms of 30 C...

A tight regulation of transcription factor activity is critical for proper development. For instance, modifications of RUNX transcription factors dosage are associated with several diseases, including hematopoietic malignancies. In Drosophila, Myeloid Leukemia Factor (MLF) has been shown to control blood cell development by stabilizing the RUNX transcription factor Lozenge (Lz). However, the mechanism of action of this conserved family of proteins involved in leukemia remains largely unknown. Here we further characterized MLF's mode of action in Drosophila blood cells using proteomic, transcriptomic and genetic approaches...

The epidermal growth factor receptor (EGFR) is the major driver of non-small cell lung carcinoma (NSCLC). Mitochondrial accumulation of EGFR has been shown to promote metastasis in NSCLC, yet little is known about how the mitochondrial localization of EGFR is regulated. In this work, we show that Tid1 (also known as mitochondrial HSP40) is involved in the mitochondrial localization of EGFR, and that the DnaJ domain of Tid1-S is essential for the Tid1-S-mediated transportation of EGFR into mitochondria. Overexpression of Tid1-S increased the migration and invasion of NSCLC cells cultured in vitro...

Leptospira interrogans is a spirochaete responsible for leptospirosis in mammals. The molecular mechanisms of the Leptospira virulence remain mostly unknown. Recently, it has been demonstrated that an AAA+ chaperone ClpB (a member of the Hsp100 family) from L. interrogans (ClpBLi) is not only essential for survival of Leptospira under the thermal and oxidative stresses, but also during infection of a host. The aim of this study was to provide further insight into the role of ClpB in the pathogenic spirochaetes and explore its biochemical properties...

OBJECTIVE: Thermotolerant species of the genus Campy-lobacter are the important agents causing human foodborne infections throughout the world. The aims of this study were to evaluate the presence of nine putative virulence genes in Campylobacter spp. isolated from patients and from foods (poultry meat, pork liver), to determine the resistance of Campylobacter isolates to eight antibiotic agents and to detect four resistance genes.Matherial and methods: The presence of the virulence genes cdtA, cdtB, cdtC, virB11, ciaB, wlaN, iam, dnaJ and racR was detected by polymerase chain reaction (PCR) in 94 Campylobacter spp...

Subunit vaccines that are poorly immunogenic are often combined with adjuvants for immunization. Our previous research identified a pneumolysin variant (ΔA146Ply), a Toll-like receptor 4 agonist, that was an effective adjuvant in the protection of fusion protein DnaJ-ΔA146Ply against mucosal Streptococcus pneumoniae infections. For pneumococcal vaccines, World Health Organization recommend injection as a regular vaccination approach. Subcutaneous immunization is a common and effective method of injection, so we explored the immunity mechanism of subcutaneous immunization with DnaJ-ΔA146Ply...

There is an enormous need to make better use of the ever increasing wealth of publicly available genomic information and to utilize the tremendous progress in computational approaches in the life sciences. Transcriptional regulation of protein-coding genes is a major mechanism of controlling cellular functions. However, the myriad of transcription factors potentially controlling transcription of any given gene makes it often difficult to quickly identify the biological relevant transcription factors. Here, we report on the identification of Hnf4a as a major transcription factor of the so far unstudied DnaJ heat shock protein family (Hsp40) member C22 (Dnajc22)...

The present study was conducted to isolate and characterize the molecular epidemiology of the methicillin-resistant staphylococci in the general university environment, where all five locations; the library, restrooms, canteens, computer rooms and outdoor surfaces, are in common use by a large population of students. We used Mannitol Salt Agar (MSA) supplemented with 4 μg/ml of oxacillin to screen the methicillin-resistant staphylococci. The species level was identified by PCR of rdr (Staphylococcus epidermidis), groESL (Staphylococcus haemolyticus) and nuc (Staphylococcus aureus and Staphylococcus warneri) genes and DNA sequencing of tuf and dnaJ genes...

Production of functional carotenoids using microalgae may facilitate the commercialization of anti-aging nutritional supplements. The green alga Chlamydomonas reinhardtii uses a non-mevalonate (MEP) pathway for isopentenyl diphosphate (IPP) synthesis. Two enzymes thought to play important roles in this MEP pathway to IPP synthesis are 1-deoxy-D-xylulose 5-phosphate synthase (DXS) and reductase (DXR). DnaJ-like chaperone (Orange protein) is thought to support phytoene synthase, a key enzyme in plant carotenoid synthesis...

The folding of newly synthesized proteins in the endoplasmic reticulum (ER) is assisted by ER-resident chaperone proteins. BiP (immunoglobulin heavy-chain-binding protein), a member of the HSP70 family, plays a central role in protein quality control. The chaperone function of BiP is regulated by its intrinsic ATPase activity, which is stimulated by ER-resident proteins of the HSP40/DnaJ family, including ERdj3. Here, we report that two closely related proteins, SDF2 and SDF2L1, regulate the BiP chaperone cycle...

Synapses must be preserved throughout an organism's lifespan to allow for normal brain function and behavior. Synapse maintenance is challenging given the long distances between the termini and the cell body, reliance on axonal transport for delivery of newly synthesized presynaptic proteins, and high rates of synaptic vesicle exo- and endocytosis. Hence, synapses rely on efficient proteostasis mechanisms to preserve their structure and function. To this end, the synaptic compartment has specific chaperones to support its functions...

To understand the biogenesis of the thylakoid membrane in higher plants and to identify auxiliary proteins required to build up this highly complex membrane system, we have characterized the allelic nuclear mutants high chlorophyll fluorescence222-1 (hcf222-1) and hcf222-2 and isolated the causal gene by map-based cloning. In the ethyl methanesulfonate-induced mutant hcf222-1, the accumulation of the cytochrome b6f (Cytb6f) complex was reduced to 30% compared with the wild type. Other thylakoid membrane complexes accumulated to normal levels...

The DnaJ proteins which function as molecular chaperone played critical roles in plant growth and development and response to heat stress (HS) and also called heat shock protein 40 based on molecular weight. However, little was reported on this gene family in pepper. Recently, the release of the whole pepper genome provided an opportunity for identifying putative DnaJ homologous. In this study, a total of 76 putative pepper DnaJ genes (CaDnaJ01 to CaDnaJ76) were identified using bioinformatics methods and classified into five groups by the presence of the complete three domains (J-domain, zinc finger domain, and C-terminal domain)...

Hsp70 molecular chaperones play an important role in maintaining cellular homeostasis, and are implicated in a wide array of cellular processes, including protein recovery from aggregates, cross-membrane protein translocation, and protein biogenesis. Hsp70 consists of two domains, a nucleotide binding domain (NBD) and a substrate binding domain (SBD), each of which communicates via an allosteric mechanism such that the protein interconverts between two functional states, an ATP-bound open conformation and an ADP-bound closed conformation...

The interaction between the Heat Shock Proteins 70 and 40 is at the core of the ATPase regulation of the chaperone machinery that maintains protein homeostasis. However, the structural details of the interaction remain elusive and contrasting models have been proposed for the transient Hsp70/Hsp40 complexes. Here we combine molecular simulations based on both coarse-grained and atomistic models with coevolutionary sequence analysis to shed light on this problem by focusing on the bacterial DnaK/DnaJ system...

Heat shock proteins (Hsps) co-operate in multi-protein machines that counter protein misfolding and aggregation and involve DNAJ (Hsp40), HSPA (Hsp70), and HSPH (Hsp105α). The HSPA family is a multigene family composed of inducible and constitutively expressed members. Inducible HSPA6 (Hsp70B') is found in the human genome but not in the genomes of mouse and rat. To advance knowledge of this little studied HSPA member, the targeting of HSPA6 to stress-sensitive neuronal sites with components of a disaggregation/refolding machine was investigated following thermal stress...

Breast cancer is the most common cancer type and cause of cancer-related mortality among women worldwide. New biomarker discovery is crucial for diagnostic innovation and personalized medicine in breast cancer. Heat shock proteins (HSPs) have been increasingly reported as biomarkers and potential drug targets for cancers. HLJ1 (DNAJB4) belongs to the DNAJ (HSP40) family of HSPs and is regarded as a tumor suppressor gene in lung, colon, and gastric cancers. However, the role of the HLJ1 gene in breast cancer is currently unknown...

The response of Clostridium tyrobutyricum to butyric acid stress involves various stress-related genes, and therefore overexpression of stress-related genes can improve butyric acid tolerance and yield. Class I heat shock proteins (HSPs) play an important role in the process of protecting bacteria from sudden changes of extracellular stress by assisting protein folding correctly. The results of quantitative real-time PCR indicated that the Class I HSGs grpE, dnaK, dnaJ, groEL, groES, and htpG were significantly upregulated under butyric acid stress, especially the dnaK and groE operons...

Mediator complex subunit 1 (Med1)/Thyroid hormone receptor-associated protein 220 (TRAP220), an essential component of thyroid hormone receptor-associated proteins (TRAP)/mediator, plays important roles in hormone responses and tumorigenesis. However, the role of Med1 in the DNA damage response has not been studied. In this study, we found that DNA damage, resulted from γ-irradiation, ultraviolet (UV)-irradiation, or hydroxyurea, induced phosphorylation of Med1 in vivo. Phosphorylation of Med1 was abrogated by either caffeine or wortmannin treatment, suggesting that Med1 is phosphorylated through the DNA damage checkpoint pathway...

Previously, we have identified a novel E3 ubiquitin ligase, BNTR1, which plays a key role in heat stress response in Brassica napus. In this study, we accidentally found that BNTR1 can also improve thermal tolerance and reduce growth inhibition at 42°C in Escherichia coli, in a manner different from that in plant. We show that BNTR1 activates E. coli heat-shock response at low concentration in soluble form instead of in inclusion body, but BNTR1 is not functioning as a heat-shock protein (HSP) because deficient temperature-sensitive mutants of HSP genes display unconspicuous thermal tolerance in the presence of BNTR1...